Implement uploading of files for model fine-tuning to OpenAI API

[sweep-ai]

Description

This PR implements the functionality to upload files for model fine-tuning to the OpenAI API. It adds a new method uploadFineTuneFile to the SoakpProxy class, which uses the OpenAI API's createFile method to upload the file. The purpose is set to 'fine-tune'. Additionally, a new endpoint POST /openai/fine-tunes/upload is added to the OpenaiFinetunesApi class, which handles the HTTP request for file upload and calls the uploadFineTuneFile method in the SoakpProxy class.

To ensure compatibility with the OpenAI API, the uploaded files are converted into JSONL format using Python means. The conversion functionality is added to the OpenaiFilesApi class.

Summary of Changes

• Added uploadFineTuneFile method to SoakpProxy class to upload files for model fine-tuning to the OpenAI API.
• Added POST /openai/fine-tunes/upload endpoint to OpenaiFinetunesApi class to handle file upload requests.
• Added convertToJSONL method to OpenaiFilesApi class to convert uploaded files into JSONL format.

Fixes #153.

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To checkout this PR branch, run the following command in your terminal:

git checkout sweep/upload-files-for-fine-tuning

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